Abstract

We demonstrate the use of self-assembledmonolayers of silica microspheres as selective growth masks for significant threading dislocation density reduction in GaN on sapphire epilayers. During GaN regrowth through the close-packed monolayer, the silica microspheres effectively terminate the propagation of threading dislocations. As a result, the threading dislocation density, measured by large area atomic force microscopy and cathodoluminescence scans, is reduced from to . This nearly two orders of magnitude reduction is attributed to dislocation blocking and bending by the unique interface between GaN and silica microspheres.

We acknowledge support from the Department of Energy Office of Basic Energy Sciences and Sandia’s Laboratory Directed Research and Development program. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Co., for the United States Department of Energy’s National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.